1. Field of the Invention
The present invention relates to a cartridge used in an electrophotographic image forming apparatus, a winding member used in the cartridge for winding a sealing member, and an assembling method for the cartridge.
2. Description of the Related Art
Conventionally, an electrophotographic photosensitive drum and a process unit, which performs processing on the electrophotographic photosensitive drum, are integrally formed in a cartridge in an electrophotographic image forming apparatus using an electrophotographic image forming process. The electrophotographic image forming apparatus employs a process cartridge system in which the above-described cartridge can be detachably mounted in the main body of an electrophotographic image forming apparatus.
The process cartridge system allows a user to perform the maintenance of the image forming apparatus without calling a serviceman, thus greatly improving the operability of the image forming apparatus. The process cartridge system is thus widely used in electrophotographic image forming apparatuses.
In an image forming apparatus, a beam of light modulated with image formation information is projected onto an electrophotographic drum (hereinafter referred to as a photosensitive drum) from a laser, an LED, a lamp, or the like. As a result, an electrostatic latent image is formed on the photosensitive drum.
A developing device then develops the electrostatic latent image, and the developed image formed on the photosensitive drum is transferred to the recording medium. The image is thus formed on the recording medium.
The process cartridge includes a developing roller as a developing unit for supplying developer (hereinafter referred to as toner) to the electrostatic latent image formed on the photosensitive drum. The process cartridge further includes a toner supplying roller that supplies toner to the developing roller, a developer container that includes a developer regulating member that regulates the toner on the developing roller, and a toner container that stores the toner.
Further, a toner discharge opening is provided on the toner container for supplying toner to the developer container. The toner discharge opening is sealed by a sealing member when a process cartridge is not yet used.
When the process cartridge is used for the first time, the user tears off the sealing member by pulling a pulling member (e.g., a pull tab) disposed on an end of the sealing member.
Moreover, the number of times for users to pull off the sealing member may increase, because color image forming apparatuses have been widely spread in these days.
There is a method of automatically removing the sealing member which seals the discharge opening by heat welding when the process cartridge is installed in the image forming apparatus main body (e.g., refer to U.S. Pat. No. 6,512,903). U.S. Pat. No. 6,512,903 discusses removing the sealing member by rotating a winding member to which one end of the sealing member is fixed, using a driving force transmitting device such as a motor-driven gear.